Hydraulic converter



y 6, 1958 G. w. LEWIS 2,833,219

HYDRAULIC CONVERTER Filed Aug. 18, 1954 2 SheetS -Sheet 1 30 ,2 0 o 29 2D 25 H i i2 I6 Z3 Z5 4,2.J 4/ 5,2

57 x 65 42 67 6/ 7: 60 7/ 88 73 70 49 :2 7 74 8/ Q 78 79 E A 76 I05 I05P IN V EN TOR.

74 George W Lewis T M \J 73 I :1-

United States PatentD 7;

HYDRAULIC CONVERTER George W. Lewis, Toledo, Ohio Application August 18,1954, Serial No. 450,774

Claims, (Cl. 10350) This'invention relates to fluid pressure apparatusand more particularly to means and method for eflecting the conversionof low sub-atmospheric fluid pressure to a substantially highsuper-atmospheric fluid pressure which has particular utility as asource of power for the operation of accessories of self-propelledvehicles.

The invention comprehends a power system in which fluctuatingsubatmospheric fluid pressure of very low value is used as imput meansfor establishing a liquid at high super-atmospheric maintained withinpredetermined values as its output to provide a substantially constanthydraulic power source.

The invention comprises a means and a method whereby variable fluidpressure of low value such as engine manifold vacuum is converted intohydraulic pressure of high value regulated and maintained withinpredetermined limits to provide an ample source of hydraulic power at apretetermined high value permitting periodical withdrawals in relativelylarge amounts.

The invention contemplates apparatus for the production and storage ofpower involving a pressure generating or pumping mechanism operated bymotor means actuated by engine manifold vacuum for charging apressurized accumulator, which pressure generating or pumping mechanismis automatically stalled when a predetermine pressure is reached.

The invention embraces an integrated assembly inwhich are structurallycombined a container for a liquid at substantially atmospheric pressuredirectly connected to a pumping mechanism operable by engine manifoldvacuum for charging a pressurized reservoir which provides a source ofsupply of an ample quantity of liquid at a'predetermined workingpressure.

The invention is concerned with a self regulated energy converting andstoring unit for pressurizing a motive medium into small space toestablish its working pressure and accumulating a reserve which isautomatically replenished so that the working pressure of the motivemedium is maintained even though the rate of delivery materially exceedsthat of accumulation.

The invention includes an inherently self-regulating ,hydraulic unitcomprising a diaphragm motor operated by the intermittent application ofengine manifold vacuum in which its diaphragm is connected to ,aspring-loaded plunger for establishing the operating pressure of themotive fluid by charging a pneumatically pressurized accumulator.Thecomponent parts of the unitare very inexpensive to make,.highlysuitablefor mass production manufacture, producing an assembly of greatsimplicity, very quiet in operation, and having comparatively smalloverall dimensions. 7

According to the foregoing summary of theinvention indicating itsgeneral nature and substance, one of its objects is to provide apparatuswhich produce a high pressure hydraulic power supply systembyconvertingfluctuating sub-atmospheric fluid pressure of low value Patented May 6,19 58 predetermined limits as a source of motive power of -by-apneumatic source wherein no adverse interference takes place between thepneumatic andhydraulic sources or the eflicient operation of therespective components. Another object of the invention is to provide asystem including means for the production and storage of hydraulicpower, providing an ample supply and an instantaneous delivery of amotive fluid at a desired-working pressure maintained withinpredetermined limits without the use of conventional valving mechanisms.

Another object of the invention is the provision of a self. containedconversion power unit of relatively small size in which anon-compressible fluid is pumped from a reservoir maintained atatmospheric pressure into a pressurized tank functioning to establish apredetermined working pressure and automatically replenish the-amount offluid stored in the pressurized tank so as to maintain an ample supply.1

' Another object of theinvention is the provision of a power unitcomprising a plurality of detachable subassemblies which are designedfor .independent calibration and for quick'and effective assembly toproduce a :hermetically sealed unit where maximum utilization of spaceis accomplished.

Aufurther object of the invention'is to provide an economicallymanufactured self-integratedpower unit formed of detachablesub-assemblies eflectively joined in axial alignment and which can beeasily and quickly assembled and disassembled for inspection-andsubstitution, as well .as for service and replacement in the fieldwithout the use of-complex equipment or special tools. A further objectof the invention is the provision of an integrated power. unit inwhichare. structurally combined and axially positioned a diaphragmmotor, voil pumping mechanism, and pressure accumulator and wherein thepumping mechanism .is surrounded by liquid'retained in a-reservoirforming an outer housing providingfla'weatherproof assembly.

Still a further object of the inventioniis to provide an integratedassembly in which are structurally combined a reservoir for a liquid atatmospheric pressure directly connected and surrounding a pumpingmechanism which .derives its actuating power from motor means:responsive and actuated by; engine manifold vacuum to charge apressurized accumulator, the latter providing an ample sourceof supplyof liquid under pressure as tlremotive power.

Otherobjects and advantages of this invention relating to thearrangement, operation and function'ofthe'related elements of thestructure, to various details of construction,- to combinations of partsand to economies of manufacture, will be apparent to those skilled inthe art upon consideration; of the following description and appendedclaims, reference being hadto theaccompanying drawings forming apart ofthis specification wherein like reference characters designatecorresponding-parts in theseveral views.

Fig. I is a side view illustrating the device of the invention anditsconnection to an engine;

Fig, ,II is. across sectional view of the device incorporati nga form ofthe invention shown in Fig. I;

such as the engine manifold vacuum, into hydraulic pressure of highvalue regulatedand maintained within gzEig. ,-I II- i s enlargedfragmentary view. ofnthe control valves for the pumping mechanism;

Fig. IV is across sectional, view taken on line's'lv lv of Fig. IIIlooking in thedirection of the arrows.

Fig. V is an enlarged fragmentary view of the valving nection betweenthe pneumatic motor ,and .thepumping mechanism;

Fig. VIII is an enlarged fragmentary view showing connecting members inassembled relation;

Fig. IX is a cross sectional view of a device incorporating a modifiedform of the invention;

Fig. X is a top plan viewof the device shown in Fig. IX;

Fig. XI is an enlarged detailed view of the control valves for thepumping mechanism shown in Fig. IX.

Fig. XII is an enlarged top planview of one of the control valves .ofthe pumping mechanism .shown in Fig. XI. a

The drawings show illustrative embodiments of the invention indicating afew. of the various ways in which its principles can be mechanicallyexpressed. However. it

is to be. understood that the invention should not be limited to thearrangements disclosed, but it is contemplated to use the principles ofthe invention in any other arrangements mother uses whenever the samemay have been foundtobe applicable. J

In the practice of the invention toprovide a hydraulic power system tosupply a high working force for assisting .the driver of an.automotivevehicle in the effective operation, :ofits controls and inthe operation of other components or accessories,.soas to materiallyreduce the efiort exerted by the driver, the apparatus and components ofthe systemxhave beendesigned to fully incorporate minimum weight andspace for a given work capacity as wellas trouble-free operation.Incorporating these factors in the invention illustrated in the drawingsthere is provided alight weightand compact inherently regulatedpressuregenerating unit for etfecting the conversion of the enginemanifold vacuum into comparatively high hydraulic pressure .ofsubstantially constant'value without the necessity of. conventionalunloading pressure regulating and relief valves The conversion orpressure gencrating unit' broadly comprises three separablecompon- .entswhich may be. termed as'a pneumatic motor or low fluid pressure. motormeans; a non-compressible fluid-supply and pumping mechanism orhydraulic pressure generator means; and a'gas pressurized reservoir oraccumulator forming the high pressure hydraulic'storing and supply meansof the system, to providean ample quantity of liquid at apredeterminedworking pressure maintained substantiallyconstant withinpredetermined limits.

The low fluid pressure motormeansorthe pneumatic motor is preferably ofthe reciprocating type provided with an output or work-preformingmember, the latter is actuated by displaceable means which areresiliently biased to the work-preforming position; The displa'ceablemeans are moved to the energy-storing position causing thedistortionofitsresilient biasing means when subjected to pressuredifierential obtained byithe application of the engine manifold vacuumand thereby effect the translation of the engine manifold vacuum intomechanicalpowef.

The application of the engine manifold 'vacuurrr is periodicallyinterrupted touproduce the reciprocationof the work-performingmember ofthe pneumatic motor. The interruption of the engine manifold vacuum tothe displaceable means of the pneumatic motor instantaneously releases,as a driving force, in the resilient means. a I

The instantaneous release of the mechanicalpower stored by theapplication of engine manifold-vacuum to the mechanical power stored theexpansible means of the pneumatic motor is utili'zed to operate theliquid pumping mechani sm orhydraulic pneumatic motor casing.

pressure generator, whereby, mechanical power is transferred intohydraulic power by pressurizing a liquid, forcing and storing the sameinto the accumulator or the the high-pressure hydraulic storing andsupply means. The utilization of resilient means as a driving force forthe power stroke of the hydraulic generator, provides means whereby thetranslation or transfer of mechanical power into hydraulic power isinherently regulated when the pressure of liquid in the accumulatorreaches a predetermined value and in addition serve as means, dependingfor its function upon the hydraulic power used, to constantly maintainan ample supply of liquid under pressure in the'accumulator.

Referring to the drawings and particularly to Figs. 1 and II in whichthe connections and constructional features of a form of the inventionare illustrated, an automotive variable speed internal combustion engine10 is shown having an intake manifold 12, to which is connected by asuitable conduit, 13 the low pressure means or pneumatic motor whichforms the upper section of the power unit of the invention.

The pneumatic motor of the invention is preferably of the reciprocatingtype in which its displaceable piston means or movable wall, as shown inthe drawing, takes the form of a diaphragm 15 made of suitable flexiblematerial clamped at its periphery by the planar bolting flanges of thetwo frustro-conically-shaped members 16 and 17, preferably made of sheetmetal, which form the The member 16 and the diaphragm 15 form ahermetically-sealed chamber 18 supporting on the top of its planarsurface 19 the automatic valve mechanism carried by the valve block 20which is detachably mounted thereon by suitable means usch as the screws21. The planar surface 19 is pierced, providing a centrally-locatedenlarged aperture 23 which allows the communication of the interior ofthe chamber 18 with a source of less than atmospheric pressure by theannular suction or air outlet port 24 provided on the bottom surface 25of the valve block, which port, through the passage 26 and the conduit13 threaded thereon, is connected to the engine intake manifold 12. Inaddition, the enlarged opening 23 of member 16 permits the communicationof the chamber 18 with the vertically-directed passageway 27 which leadsto the annular atmospheric venting or air inlet port 28 formed on thetop surface 29 of the valve block.

An air cleaner and sound-deadening assembly is interposed between theatmosphere and the air inlet port 28. This asembly, as shown in thedrawing, comprises a side perforated, cup-like member 30 carrying, atits inner top section, a smaller, cup-likemembcr 31 having its dependingwalls terminating above the valve block 20 into an outwardly-projectingperipheral flange, thereby forming an annular space 32 in which issuitably retained sound-deadening as well as filtering material.

, "The air outlet and inlet ports 24 and 28 provided in the valveactuating mechanism which embodies a pair of planar disc-like valvemembers 34 and 35 interconnected by the valve stem 36. The valves 34 and35 are alternately seated or unseated closing the corresponding ports bythe movement of the diaphragm 15 through the instrumentality of asnap-over spring arrangement.

The planarvalve members 34 and 35 are inaxial alignment and the valve 34is arranged to normally close the air inlet port 28 while the valve 35,forming an integral part of the stem 36, is unseated with respectto airoutlet port 24 or held in its open position. Means are provided foradjusting valve clearances for optimum operation and alsopermit-alignment of the valve member with its corresponding valve seat29 to effectively close the air inlet port 28 These means areparticularly shown in Fig. V where it can be seen that the valve member34 is mounted on the threaded end 37 of the valve stem36 and is adaptedto be held in adjusted position by suitable asses- 1 9iocking'means-such as-a'wi're passing through an opening provided in thevalve stem '36 and the castellations formed ing thereby a very reliableoperation of the motor. This connection and arrangement'may take theform of a pair of U-shaped members or similarly'shaped yokes 40 and 41facing each other and'arranged at'substantially right angles, so thattheir leg portions are'directed in opposite directions. The member is'detachably connected to the threaded end 38 of thevalve stem 36 and iscapable of adjustment thereon through its central threaded opening andlock'nut 42.

As particularly shown in Fig. VI, the legs ofthe 'U-shaped member 40 areprovided with rectangular,

aligned apertures 43 which freely admit the passage of the end portionsof the oppositely extending arms 45 and 46 of the cross-shaped flatspring 47 which also has the ends of'its opposed arms 48 and 49projecting through the rectangular, aligned apertures 50' formed on theupwardly directed legs of the U-shaped member '41. The relationship ofthe comparatively large openings 43 and 50 with respect to the thickness'of the end portions of the uniplanar cross-shaped leaf spring "47provides the limited lost motion and a resilient play connection wherebythe spring performs the snap over action at the opposite limits ofmovement of the diaphragm for simultaneously changing the position ofthe valves 34 and 35.

The yoke member 41 is fixed to thediaphragm by riveting the same on topof the diaphragm reinforcing plate-52 through the upsetting of the endof the reduced shouldered portion-53 of thepneumatic motorwork-performing member 54. The reduced portion 53 passes through centralopenings provided in the diaphragm 15 and reinforcing plates 53 and 56with its shoulder abutting the lower surface of plate 56 providing arigid connection between the diaphragm 15 and output member 54 as wellas means to hold the same in fixed and leakstored power to urge theoutput means of the motor to its work-performing position at asubstantiallyconstant force or pressure of a yieldable character wherebythe motor is inherently regulated to provide a predetermined drivingforce. The distortable resilient means may take the form of a spring 57,preferably of the compressible coil type, arranged to' surround theoutput member 54 with its upper end bearing against the bottom surfaceof the casing member 17 and retained in position by engaging thedepending flange 59 which defines its central aperture. The lower end ofthe spring 57 is in engagement with the horizontally disposed flange 60of the cuplike spring retainer 61 (see Figs. VII and VIII), which isconnected to the output member 54 through its detachable wrist orconnecting pin 62, so that the diaphragm as to provide a type of bayonetconnection for its rapid and ready assembly and disassembly, and it isprovided with downwardly-projecting portions 64 at right angles to theaperture 63 for holding the retainer 61 in nonremovable positiomasshownin Fig. VIII.

The pumping mechanism or hydraulic pressure gen *erator means of theinvention is driven by the pneumatic "motor through a :dem'ountablepower-transmitting Icon- -nection provided in the end portion of'the'work-performing member'54. This connection is shown in the form of aclevis 65 adapted to receive the planar perforated end section 67 of thecylinder plunger 68 constituting the reciprocable piston means of thehydraulicpumping mechanism. The clevis 65 and the section 67 of the.piston 68are interconnected'for power transmission-by means of thereadily detachable connecting pin 62.

The piston 68 of the pressure generator is adapted for slidin movementin the central bore 69 of the hydraulic pump body 70 forming thecylinder therefor, provided at "its upper end with liquid-tight sealingmeans 71. "The pump cylinder 70 is provided with a lateral cylindricalaperture for the entrance of the hydraulic liquid forming the inlet port72 which is. controlled by alight-weight ,and low-friction valve member73 of thin metal, preferably of'square shape. The valve member 73 isoperablein response to the motion of the piston 68 topermitthe entranceof the liquid into the cylinder chamber 69 when .thepiston is retracted.and closed during its pumping having its outer end 78ithreadedlyconnected tothe top member 79 of the accumulator housing. The. dischargepassage 80 of the pump is adapted to beclosedby a oneway valvecomprising ball 81 urged against its valve seat 82 by's'pring 83suitably retained'therein.

The pumping mechanism is enclosed by a tubular member 85, preferably ofthin metal which performs .the double function of connecting thepneumatically-operated motorand the pressurized accum-ulatorthrough therespective bolting flanges, and of forming a container for retaining atatmospheric pressure a supply of hydraulic liquid, preferably oilsurrounding the pressure-producing mechanism. The member 85 adjacent itstop section has an opening 86, to which is connected a tubular member-87 for filling the container 85 with hydraulic liquid tma predeterminedlevel and which is closed by a vented and filter cap'provided with alevel stick 88, by means of which the level of the liquid can be readilyascertained. The tubular member. 87 is also provided with a threadedopening 89, to which is connected the end of a conduit 90 used forreturning thehydraulic liquid delivered/by the accumulator. The bottomflange 91 of member .85,

secured by means of suitable bolts 92 to the under side of the boltingflange 93 of the cup-like member '94 which forms the lower section ofthe accumulator outer shell or housing. i U

The accumulator or high pressure storing and supply means used toestablish a predetermined high-Working pressure having a range including1,000p. s. i. for the hydraulic liquid transferred therein by thepumping mechanism may take any of the conventional forms. .In theembodiment illustrated, the accumulator shown'is of the piston typepermanently biased 'to oneposition by means housed therein which arepreferably in theform of a compressible fluid under a predeterminedpressurev and comprises a movable member or piston 95 dividing theinterior of the accumulator shell into opposed chambers 96 and 97. Thechamber 96 constitutes the liquid-storing space, and the chamber 97, acompressible .cushiorn'ng spa-cc adapted to permanently contain or:becharged 'as .requiredwith a compressible fluid, preferably adryinertgas, by means of the one-way valve 98.

,assaaie The movable piston 95 of the' accumulator unit is of dome-likeconfiguration provided with suitable sealing means to preventinterconnection between the oil storing compartment 96 and the.compressible cushioned space 97 in order to maintain the sweat theirpredetermined pressures The sealing means may take the form of anO-ring" 100 located in a rectangularly shaped groove 101 formed on thedepending cylindrical wall section 102 of the piston which has aslidingfit with the cylindrical liner 104 secured to the inner surfaceof the section 94 by welding 105. The oil or hydraulic liquidtransferred 7 and forced by the pump plunger 68 from the container 85into the pressurized storing chamber 96 of the accumulator is adapted toflow out or be delivered through the passageway 106 leading by'connector 107 to the high pressure delivering conduit109 of thehydraulicpower system, providing thereby a hig-h working force atsubstantially constant value to assist the driver of an automotivevehicle in the operation of its controls and the accessories orpower-operated assemblies hydraulically actuated. t

The operationrof the conversion power unit is believed to be apparentfrom the foregoing, and can be summarized as follows. With the partsarranged in powerdelivering position, as illustrated in Fig. II, thesource of less than atmospheric pressure connected to the motor unitwill create a negative or sub-atmospheric pressure in the chamber 18 asthe inlet valve 34 is closed, and the outlet valve 35 is opened,permitting the air in the chamber 18 to be drawn and escape through theoutlet port 24 and the conduit 13 into the engine intake manifold,creating a pressure differential between the chamber 18 and itssurrounding atmosphere. This pressure differential causes the diaphragm15 to be flexed upwardly, exerting a lifting force against the tensionof the power spring 57, distorting the samejfor storing energy thereinand concurrently retracting the piston 68 by its output working member54 whereby oil will be drawn through the inlet port 72 into the pumpchamber 69 from the supply surrounding the same.

As the diaphragm 15 is flexed upwardly, the crossshaped spring 47 isalso flexed in the same direction as the yoke 40 is held stationary byits rigid conection with the air inlet valve 34 which is maintainedclosed by pressure from the outside atmosphere. When the diaphragm 15reaches substantially the limit of its lifting movement or its extremeupward position, the force produced by the flexure of the cross spring47 is sufiicient to overcome the opening resistance of the valve 34 andthe central portion of the spring will produce the snap-over action toclose the valve 35 and thereby stop the application of engine manifoldvacuum to chamber 18 and open the valve 34, subjecting to the atmospherethe chamber 18. The opening of the valve 34 will cause air to rushthrough the inlet port 28 into chamber 18 under atmospheric pressure andthereby instantaneously release as a driving force the energy or powerstored through the distortion of the spring 57 to'propel the diaphragm15 and its output member 54 downwardly and effect the pumping stroke ofthe piston 68 of the hydraulic pressure generator of the powerconversion unit.

During the initial downward movement of the pump piston 68 to producethe pumping stroke, the movement of the oil or hydraulic liquid in pumpchamber 69 will force the valve 73 againstits seat 73', preventing arecession of oil into its reservoir. The pumping stroke of piston 68will open the ball valve 81, discharging the pump chamber, whereby theoil is forced into the accumulator chamber 96 against the compressiblemeans or pressurized gas contained in chamber 97 to establish apredetermined high-working pressure for the oil transferred and storedin chamber 96 whereby variable engine intake manifold vacuum isconverted into hydraulic pressure of highvalue. It should be noted thatas the diaphragm 15=moves downwardly, the leaf spring 47 is also flexeddownwardly as the outlet'valve 35 is held in its closed ing mechanisms.

position due to pressure differential between the chamber 18 and theconduit 13 connected to the source of less than atmospheric pressure.

The outlet valve 35 of thepneurnatic motor will be maintained in itsclosed position until the diaphragm 15 reaches substantially the limitof its downward movement when the force produced by the flexing ofspring 47 will be sufficient to overcome the opening resistance of valve35 whereby the spring will effect its snap-over action, opening valve 35and simultaneously closing valve 34. The component parts .of the limitedlost motion or play connection between the diaphragm 15 and the valvemechanism are so arranged and proportioned that when the diaphragm 15 isflexed by the action of spring 57 to substantially extreme downwardposition, the flexing force of the cross spring 47 is suflicient toovercome the opening resistance of the outlet valve 35, effecting thesnapover action and rapidly moving downwardly the valve 35 to its fullopen position and simultaneously closing the valve 34. The parts willthen be again in the position shown in Fig. II, ready to resume anothercycle of operation.

The cycle of operation hereinbefore described will be automaticallyrepeated to gradually build up pressure for the oil transferred by theplunger 68 into the chamber 96 moving the piston downwardly by acting onthe upper side in opposition to the progressibly increasing resistanceon its other side caused by the compression of the pressurized gas inchamber 97 untilthemaximum predetermined working pressure is establishedfor the oil stored therein, at which time the motive or driving force isinsuflicient to perform the working stroke of the plunger 68, so thatthe pressure generator is stalled or rendered ineffective whereby theconversion unit is inherently regulated without the use of conventionalvalv- The stalling of the pressure generator takes place when the poweror driving force produced by the instantaneous release of the energystored in the spring 57 is balanced or is insuflicient to force oil intothe chamber 96 to further move the piston 95, so that the transfer ofoil by the'plunger 68 into the accumulator is inherently stopped. Whenthis condition occurs, the valves 34 and 35 of the pneumatic motor willtake the position shown in Fig. II due to the limited or lost playconnection between the diaphragm 15 and the .valve mechanism.

It should be noted that whenever the oil stored in the accumulatorchamber 96 at a predetermined working pressure is discharged or used asa source of power through the high pressure delivering conduit 109, thecycle of operation will be resumed and the amount of oil discharged fromchamber 96 will be automatically replenished as the power conversionunit of the invention is designed to maintain, at all times, an amplesupply of hydraulic liquid at a predetermined high-working pressure,providing thereby a hydraulic power system for assisting the driver ofan automotive vehicle in the op oration of controlling devices andaccessories.

In the embodiment of the invention illustrated in Figs. IX to XIIinclusive of the drawings, the principles and general arrangements ofthe main components of the power unit hereinbefore outlined, used toobtain the conversion of fluctuating sub-atmospheric pressure of lowvalue into substantially constant pressure of high value, aresubstantially the same as those shown in Figs. I to VIII inclusive. Thepneumatic motor operable in response to a source of pressure differentthan atmosphere, as shown in Fig. IX, is of the reciprocating typehaving a movable wall in the form of a flexible diaphragm ofsubstantially rectangular shape, clamped at its periphery by the planarbolting flanges of the two rectangularly-shaped, dish-like members 116and 117, preferably made of sheet metal which form the motor casing. Themember 116 forms with the diaphragm 115, a her- 124. 'for the valveClearances, and obtain thereby optimum metically sealed chamber 118carrying on the top 'of'the planar surface .119 the valve block'1'20mounted in sealed relation thereon by suitable gasket and the screws121. The planar surface 119 has an enlarged aperture 123 whereby theinterior of the chamber 118 is in communication with the annular'suctionor air outlet port 124 formed on the bottom surface 125 of the valveblock.

The port 124, through the'passage 126 and the connector 113 threadedthereon, is adapted to be connected to an engine intake manifold. Theenlarged opening 123 also permits the communication of the chamber 118with the vertically=directed passageway 127 which leads to the annularatmospheric venting or air inlet port 128 formed on the top surface 129of the valve block 120.

Fixed to the top surface of member 130 adjacent to itsperforations is acup-like member 131 of larger diameter having its depending wallsterminating adjacent to the perforated flange provided in member 133.The space formed between the cup-like members is filled with suitablesound-deadening material 132, which also acts as an air filter.

The air outlet and inlet ports 124 and 128, provided in the valve block121 are opened and closed by the automatic valve-actuating mechanismwhich embodies a pair of planar disc-like valve members 134 and 135interconnected by the valve stem 136 passing through the central portionof the valve block 120. The valves 134 and 135 are alternately seated'orunseated closing the corresponding ports by the movement of thediaphragm 115 through the instrumentality of a snap-over springarrangement.

As shown in Fig. IX, the valve members 134 and 135 are so arranged thatwhen the valve member 134 is in open position, the valve member 135forming an integral part of the stem 136 is seated, closing the airoutlet port In order to provide a fine degree of adjustment operation,as well as proper alignment with respect to the valve seat 129, thevalve member 134 is threadedly mounted on the valve stem 136 and isadapted to be held in adjusted position by suitable locking meansinclusive of a wire passing through the valve stem 136 and castellationsformed on the valve member.

The valve stem interconnecting the valve members 134 and 135 isconnected to the diaphragm by a limited lost motion or resilient playconnection provided with a spring isnap-over action'in order to insure arapid and positive seating and unseating of the valve members in properorder and relationship to obtain thereby reliable and trouble-freeoperation of the motor. This connection and arrangement is substantiallythe same as the one shown in Fig. VI of the drawings and generallycomprises a pair of'U-shaped members 140 and 141 facing each other andarrangedat substantially right angles, so that their leg'portions aredirected in opposite directions. The top member 140 is detachablyconnected to the threaded end of the valve stem 136 and is capable ofadjustment thereon through its central threaded opening and a lock nut'by the spring performs the snap-over action at the oppo- Site limits ofmovement of the diaphragm 115 for simulita-neeusly ch'ari'ging'theposition of the vaivesls sand 135.

The u standing :U-shaped member 141 is fixed to the "diaphragm byriveting the same ontop of the diaphragm 'reinfor'cingplate 152 throughthe upsetting of the end of the reduced shouldered portion 153 of themotor work-performing or output member 154. The reduced portion 153projects through central openings :iprov'ided in the diaphragm 115 andreinforcing plates 152 and 156 and its shoulder abuts the lower surfaceof plate 1'56,'providing arigid connection between the diaphragm 115 andoutput member 154, as well as means to hold the same in hired andleak-proof relation.

In the form of the invention shown in Fig. IX, the outputmember 154 ofthe pneumatic motor is urged to its work-performing position bydistortable resilient means supporting bracket 158 which, in'turn, isfixedly secured to the stationary casing member 117 and is located inposition by an upwardly-projecting flange 159 which projects throughxthecentral aperture of the casing member.

The power spring 157, housed within the tubular section -of'the bracket.158, hasits lower end in engagement with a=horiiontally-disposedflange160 of the cup-like retainer .161, which is connected to the outputmember 154 through its detachable wrist pin 162, so that the diaphragm115, and thereby its output member 154, are resiliently biased to oneposition. The spring retainer 161 includes the same constructionaldetails shown in Fig. VII, and is arranged to provide a type of bayonetconnection with the wrist pin 162, as particularly shown in Figs. VIIand VIII, so that its rapid assembly and disassembly can be eifectivelyaccomplished;

The hydraulic pressure generator or pumping unit of the invention isdriven by the pneumatic motor through 'auniversal-ball and socketpower-transmitting connection .which'interconnects the motor andgenerator in axial alignment. This connection is shown in the form of asocket 165 formed at the end of member 154 which re tains theball-shaped section 167 formed at the "end of the cylindrical plunger.168 which constitutes the reciprocable piston means of the hydraulicpressure generator .unit.

In the modified form of theinvention the piston '168 of ,thepressure-generator is reciprocable in the central bore 169 .of thehydraulic pump body forming a cylinder therefor which, in thisembodiment, is made in three sections forea'se of manufacture and readyassembly. The sections 170, 171,2and 172 are provided with planar matingsurfaces adapted to be clamped together, forming a liquid-tightassembly, by suitable means,such as threaded bolts -173, which' also.act as means to secure the 'pump body to the lower flange 174 of thepump bracket 158 through the clamping ring 175 having threaded engage-.mentwith the clamping bolts 173.

' The central bore-169 constituting the liquid-receiving chamber is.formed'on the top section and is provided .a'tits upper endwiths'ealing means 176 whereby the piston 168. is in liquid-tightrelation during its reciprocatory movement. The planar surface. ofsection170I-forming the lower end of the chamber 169 is provided with anenlarged circular recess 177 which accommodates and permits the movementof the reciprocable light-weight annular valve 178 of thin materialprovided with upstanding lugs 178,(see Figs. XI and XII). The valvemember 178 is operable in response to the motion of the piston 1'68toperrnit the entrance of liquid into the cyl- -'indei' chamber 169'whenthe piston is retracted and closed during its pumping stroke by beingseated against the assaam top planar surface of the intermediate section171 which is provided with an annular groove forming the inlet port 179leading by a passage 179' to the enlarged annular passageway 180,uponwhich is fixedly retained the filtering screen 181.

The opening 182 of the annular valve 178 is in alignment with thechamber 169 and with the discharge passage 183 traversing section 171which is adapted to be closed by the ball member 184 urged against itsvalve seat by spring 185 reacting against the annular member 186 held insealed relation between the planar mating surfaces of sections 171 and172 by'suitable sealing means such as an O-ring 187.

The pump discharge passage 183 is intercepted below the valve member 184by a passage 188, to which is connected in fluid-tight relation thelower end of a conduit 189 leading to the connector 190 fixed on top ofthe casing member 116, constituting the high pressure delivering meansof the power conversion unit. The'bot tom section 172 of the pump bodyhas a central aperture, to which is brazed the tubular member 191forming the high pressure discharge passage which connects the pump tothe accumulator.

The cup-like member 192, preferably made of sheet metal, is secured byits top section to the bolting flanges of the pneumatic motor casing,and forms a container adapted to retain at atmospheric pressure a supplyof hydraulic liquid, surrounding the pumping mechanism. The container192 is fixedly secured by its bottom. planar section 193 through asuitable sealing gasket 193 and bolts 194 to the upper end head of thepressurized accumulator.

In the embodiment illustratedin Fig. IX, the accumulator used toestablish the working pressure for the hydraulic liquid in order toprovide a substantially constant power source for a hydraulic powersupply system having a working pressure of approximately 1,000 p. s. i.or higher if desired is of the type in which a movable piston ispermanently biased to one position by cushioning means housed therein,such as compressible fluid held under a predetermined pressure. Theaccumulator shown comprises a movable member or piston 195, by means'ofwhich its interior is divided into two opposed compartments wherein thecompartment 196 constitutes the liquidstoring chamber, and compartment197, a compressible space adapted to permanently hold or be chargedasrequired preferably with a dry inert gas, by means of a one-way valve198 carried by its casing. The accumulator casing comprises an outertubular member 200 made preferably of an ordinary piece of steel tubingclosed at both ends by curved pressure-resisting end heads having arelatively concave curvature, each formed by similarly arranged members.I i

The pressure-resisting end head which hermetically closes the lower endof the steel tube 200 comprises a planar circular member having aperipheral offset forming a flanged closure 20 1 brazed at 203 to theinnerpea riphery of the annular member 204 of spherical configuration.The outer periphery of member 204 has press-fitting engagement with theshoulder section 205 formed at the inner surface of the tube 200 and isjoined thereto by a continuous annular weld 206. It should be noted thatthe closure member 201, as hereinbefore mentioned, has at its centralportion a valve 198 which provides one-way communication with the casinginterior for the purpose of charging the accumulator with a compressiblegas.

The pressure-resisting head, which hermetically closes the upper end ofthe steel tube 200, comprises a planar circular member having aperipheral offset forming a flanged closure 207 brazed at 208 to theinner periphery of the annular member 209 of spherical configuration.The other periphery of member 209 is arranged and dimensioned to providea press-fitting engagementwith the shoulder section 210 formed at theinner surface of the 12 tube 200 and is joined thereto by a continuousweld 212. The closure 207 has a central aperture 213 in alignment withopenings formed on the planar surface 193 and on the sealing gasket 193'for receiving in leakproof relation the high pressure discharge conduit191 of the pump unit. The conduit 191 is appropriately sealed inaperture 213 by high pressure sealing means comprising an annular member214 which retains in suitable relation the 0-ring 215.

The depending boss or flange section 216 of the closure 207 is encircledby the cylindrical member 217 closing the same in sealed relation bymeans of an Daring 218 retained in the rectangular groove 219 and itsbottom surface is recessed forming a reduced planar outer section 220 soas to substantially avoid the possibility of piston 19S sticking theretoin case of a complete discharge of the liquid normally retainedinchamber 196.

The movable piston 195 of the accumulator unit is provided at its uppersurface with a central recess 221 to limit the area of engagement withthe bottom surface of the closure 207 to' avoid the possibility ofsticking thereon, and is provided with suitable sealing means to preventleakage or interconnection between the oil-storing compartment 196 andthe compressible cushioning space 197 separated by the piston. Thesealing means shown comprises an O-ring 222 located in arectangularlyshaped groove 223 formed on the depending cylindrical wallsection 224 of the piston which has a sliding fit with the inner surfaceof the cylindrical member 217 which has a working fit at its lower endwith the flange 225 of the closure 203. The cylindrical member 217 isprovided with a plurality of openings 126 located slightly above the topsurface of the flange 225, so that the space below the piston member isin communication with the annular space surrounding the same whereby thepressurized compressible gas surrounds the liquid-storing 'chamber.

As particularly shown in Fig. X, the top surface of the motor casingmember 116 is provided with a connector 227 whereby the liquid underpressure delivered by the pressure unit is returned to the container192, within which is retained at atmospheric pressure, the supply ofhydraulic liquid. The casing member 116 is also provided with anaperture for filling the container 192 with the hydraulic liquid at apredetermined level, and is closed by a perforated cap 228 provided witha level stick 229, by means of which the level of the liquid surroundingthe pumping mechanism can be readily ascertained. The conversion unit ofthe invention is adapted to be supported in any desirable positionwithin the engine compartment or within the frame-work of the automotivevehicle and, for purpose of illustration, the same is provided withsuitable supporting means, which, in the modified form of the invention,is shown as a bracket 230 fixedly secured to the outer member 200 of theaccumulator unit.

The operation of the modified form of the invention is the same as thatalready described with respect to the form shown in Figs. I to VIIIinclusive. It should be observed, however, that in Fig. IX, the partsare shown in the position which they occupy in the cycle of operationprior to the release of the stored power to effect the pumping stroke ofthe piston for transferring the hydraulic liquid into the pressurizedaccumulator.

It should be noted that in both embodiments of the invention aself-integrated unit having numerous parts of the three component unitsare arranged to serve dual purposes whereby the cost of manufacture isgreatly reduced. Moreover, the three main components of the conversionunit form unitary subassemblies suitable for independent calibration andwhich can be easily and quickly assembled and disassembled forinspection and substitution, as well as for service and replacement inthe field Without the use of special tools or complex equipment.

It is to be understood that the above detailed description of thepresent invention is intended to disclose an embodiment thereof to thoseskilled in the art, but that the invention is not to be construed aslimited in its application to the details of construction andarrangement of parts illustrated in the accompanying drawings, since theinvention is capable of being practiced and carried out in various wayswithout departing from the spirit of the invention. The language used inthe specification relating to the operation and function of the elementsof the invention is employed for purposes of description and not oflimitation, and it is not intended to limit the scope of the followingclaims beyond the requirements of the prior art.

What is claimed is:

1. In combination, a cylinder, a reciprocating piston movable in saidcylinder, a reservoir retaining a liquid surrounding said cylinder, avalve means on a wall of said cylinder open for the entrance of liquidfrom said reservoir when the piston is moved in one direction and closedupon the discharge of the liquid from said cylinder in response to themovement of the piston in a different direction, a pressurizedaccumulator of the piston type carried by said reservoir operativelyconnected to said cylinder including valve means in said connection forestablishing a predetermined working super-atmospheric pressure of highintensity for the liquid discharged from said cylinder into saidpressurized accumulator, and a diaphragm motor also carried by saidreservoir operable by engine manifold vacuum including resilient meansoperatively connected to said reciprocating piston for moving the samein its discharge stroke to thereby effect the conversion of variablesub-atmospheric pressure into hydraulic super-atmospheric pressure ofhigh intensity.

2. In combination, a pressurized accumulator, means for forcing liquidfrom a source thereof into the pressurized accumulator to establish apredetermined high working pressure for the liquid forced in saidaccumulator, a reciprocating piston and a cylinder therefor forming apart of said liquid-forcing means, valve means on the wall of saidcylinder open to effect entrance of liquid from said source when thepiston is moved in a retracting direction and closed in response to theother direction constituting the pumping stroke of the piston, the saidpressurized accumulator having a valve means connected to said forcingmeans and a piston biased to one position by a compressible fluid, acasing surrounding said forcing means acting as a liquid containertherefor and supporting at one end said pressurized accumulator, asubatmospheric fluid pressure reciprocating diaphragm motor carried atthe other end of said casing, said diaphragm motor including yieldingmeans for operating said forcing means, and the said diaphragm motoroperated by engine manifold vacuum to thereby effect the transfer of alow intensity variable sub-atmospheric fluid pressure into hydraulicpressure of high value.

3. In combination, a pressurized accumulator for storing a liquid underpressure, a movable piston in said accumulator dividing the same intoopposed chambers urged to one position by bias means housed therein, apump cylinder, a reciprocating piston in said cylinder, aliquid-retaining reservoir surrounding said cylinder and supporting atone end said pressurized accumulator, a single valve member carried bysaid pump cylinder, said single valve member responsive to the movementof said piston by being moved to open position for effecting admissionof liquid from said liquid-retaining reservoir into said cylinder andbeing moved to closed position to stop the admission of said liquidduring the pumping movement of the piston, conduit means including valvemeans directly connecting the discharge of said cylinder to saidaccumulator providing a liquid connection therebetween for effecting thedirect transfer and storage of the liquid pumped by said piston intosaid pressurized accumulator against the force of said bias means toestablish thereby a relatively high working pressure for the liquidstored in said pressurized accumulator, and a diaphragm motor alsocarried by said reservoir operable by engine manifold vacuum includingresilient means operatively connected to said reciprocating piston formoving the same in its discharge stroke to thereby effect the conversionof variable sub-atmospheric pressure into hydraulic superatmosphericpressure of high intensity.

4. In combination, a pneumatically operated diaphragm motor having anoutput member axially disposed, yielding means operatively connected tosaid output member, a hydraulic pump having a reciprocating pistonoperated by the output member of said diaphragm and being positioned inaxial alignment therewith, a pressurized accumulator having a pistonbiased to one position by compressible fluid positioned in axialalignment with said reciprocating piston, the said pneumaticallyoperated motor operated by an engine manifold vacuum to store mechanicalpower in said yielding means when the piston and output member are movedin response to the application of vacuum in a retractingdirection and torelease the stored mechanical power when the application of the enginemanifold vacuum is stopped to thereby effeet the transfer of a lowintensity variable sub-atmospheric fluid pressure into hydraulicpressure of high value, and a casing surrounding said hydraulic pump andperforming the function of supporting at opposite ends the pneumaticallyoperated motor and the accumulator,

also maintaining the axial alignment of the motor and accumulator, aswell as acting as a container for retaining at atmospheric pressure asupply of liquid surrounding said hydraulic pump.

5. In combination, a pressurized accumulator comprising an enclosingshell and a movable piston dividing the space within said shell into aliquid-storing space and a cushioning space, a pump mechanism having areciprocating piston operable to draw liquid from a supply, a singlevalve member carried by said pump cylinder adjacent its discharge end,said single valve member responsive to said piston by being moved toopen position for effecting admission of liquid from a source of supplyinto said cylinder and being moved to closed position to stop theadmission of said liquid during the discharge movement of the piston, aconduit connecting said pumping mechanism and accumulator to effect thetransferring of the liquid in the pump mechanism to the storing space ofsaid accumulator, yielding driving means connected to said pumpmechanism providing a predetermined force for effecting the dischargestroke of said pump to transfer of said liquid by said pump mechanism,said yielding means rendered inelT-ective to effect the discharge strokeof said pump mechanism when the pressure in the cushioning space of saidaccumulator reaches a predetermined maximum, valve means in said conduitoperable to inhibit the reverse flow of liquid therethrough, a diaphragmmotor operable by engine manifold vacuum to store mechanical power insaid yielding means when the piston is moved in response to theapplication of vacuum in a retracting direction and to release thestored mechanical power when the application of engine manifold vacuumis stopped to thereby effect the transfer of low intensity variablesub-atmospheric fluid pressure into hydraulic pressure of high value,and a casing supporting in axial alignment the said diaphragm motor andaccumulator and acting as a container for retaining a supply of liquidsurrounding said pump mechanism.

References Cited in the file of this patent UNITED STATES PATENTS1,390,617 Jay Sept. 13, 1921 1,825,411 Murphy Sept. 29, 1931 2,301,916Horton et al Nov. 17, 1942 2,605,716 Huber Aug. 5, 1952 FOREIGN PATENTS955,153 France Ian. 6, 1950

